Pressurized fuel metering device

ABSTRACT

A DEVICE FOR SUPPLYING METERED AMOUNTS OF FUEL AND AIR TO A MIXER OR BLENDER WHICH IN TURN SUPPLIES THE FUEL-AIR MIXTURE TO AN INTERNAL COMBUSTION ENGINE. WHEN THE ENGINE IS RUNNING, FUEL IS PUMPED UNDER POSITION PRESSURE THROUGH THE DEVICE, AND WHEN THE ENGINE IS OFF, BACK PRESSURE PREVENTS LEAKAGE OF FUEL.

United States Patent lnventor De Witt M. Fessenden 911 Summit Blvd., West Palm Beach, Fla. 33405 App]. No. 777,659

Filed Nov. 21, 1968 Patented June 28, 1971 PRESSURIZED FUEL METERING DEVICE 2 Clahnsfl Drawing Figs.

U.S. C1 123/l391 AX, 123/140MC Int. Cl. F02d 9/00 Field olSeareh 123/119, 139.11,139.12,139.14,139.15,139.16,139.17, 139.18,140.3

[56] References Cited UNITED STATES PATENTS 1,996,590 4/1935 Rockwell 123/139.18 2,228,000 1/1941 Chand1er.. 123/119X 2,348,008 5/1944 Hunt 123/139.18 2,598,202 5/1952 Wirth et a1 123/119 3,282,573 11/1966 Phelps 123/119X 3,288,445 11/1966 Mennesson 123/139.17

Primary Examiner- Laurence M. Goodridge Attorney-John 1'1. Oltman ABSTRACT: A device for supplying metered amounts of fuel and air to a mixer or blender which in turn supplies the fuel-air mixture to an internal combustion engine. When the engine is running, fuel is pumped under positive pressure through the device, and when the engine is off, back pressure prevents leakage of fuel.

PATENTED JUH28 I971 SHEET 1 0F 2 l 5-6;? INVENTOR.

oswm' M FESSENDEN.

q lllllllllllll ATT'Y PATENTED JUN28 I971 SHEET 2 OF 2 INVENTOR.

DEW'TT M. FESSENDEN.

ATT'Y.

1 PRESSURIZED FUEL METERING DEVICE BACKGROUND OF THE INVENTION Devices for mixing and blending fuel and air with recycled exhaust gases are described and claimed in two copending applications of the present inventor identified as Ser. No. 646,819 filed on June 19, 1967 now U.S. Pat. No. 3,421,485 and Ser. No. 769,508 filed on Oct. 22, 1968 (now U.S. Pat. No. 3,421,485). The present invention provides a device for supplying metered amounts of fuel and air to mixer or blender devices of the type described in these applications, although the utility of the present invention is not necessarily limited to the particular devices of the copending applications.

SUMMARY OF THE INVENTION In accordance with one embodiment of the present invention, a fuel pump supplies fuel through a check valve to a first reservoir from which fuel flows through a small idling orifice to an intake passage to provide fuel for idling of the engine. Fuel is also supplied under the pressure of the pump to a second reservoir which communicates with a metering valve and inlet leading to the intake passage. Air also flows through the intake passage, and the intake passage has a control valve. This control valve is operated in conjunction with the metering valve by means of a throttle linkage to provide a metered flow of fuel and air into the intake passage. The air intake passage leads to the mixer or blender device mentioned previously where the fuel and air are mixed. Throughout the device, the fuel is under positive pressure supplied by the fuel pump when the engine is running. When the engine is not running, the check valve closes and back pressure develops which prevents leakage of fuel through the idling orifice. The metering valve also closes to prevent leakage of fuel through the metering inlet. The first and second reservoirs provide an immediately available supply of fuel for starting the engine. The system does not drain itself if the accelerator is pumped. in the illustrated embodiment, the reservoirs, the check valve, the air intake passage, the air intake valve and the metering valve are all incorporated in a single block.

Accordingly, it is an object of the present invention to provide a device for supplying metered amounts of fuel and air to be mixed and burned in an internal combustion engine.

Another object of the invention is to provide such a metering device in which fuel is forced through the device under the positive pressure of a pump.

Another object of the invention is to provide a device for metering air and gasoline to be supplied to a mixer or blender device, the metering device having one path for supplying gasoline for idling purposes and another path for supplying fuel for acceleration purposes.

A further object of the invention is to provide a metering device as just described with a first reservoir for the idle fuel supply path and a second reservoir for the acceleration fuel supply path, these reservoirs providing an immediately available supply of gasoline for starting.

Still another object of the invention is to provide a fuel and air metering device for an internal combustion engine, the device being constructed such that all fuel flow paths are normally full of gasoline and having a valve arrangement which prevents leakage of gasoline when the engine is not running.

Other objects of this invention will appear in the following description and appended claims, reference being had to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

ON THE DRAWINGS FIG. 1 is a plan view of an internal combustion engine provided with a pressurized fuel metering device in accordance with one embodiment of the invention;

FIG. 2 is a side elevational view showing the metering device mounted on top of a mixer or blender device which in turn is mounted on the intake manifold of the engine;

FIG. 3 is a top plan view of the pressurized fuel metering device; I

FIG. 4 is a sectional view of the metering device taken along line 4-4 of FIG. 3;

FIG. 5 is a sectional view of the metering device taken along line 5-5 of FIG. 3, the pump being omitted;

FIG. 6 is a top sectional view of the metering device taken along line 6-6 of FIG. 2; and

FIG. 7 is a fragmentary perspective view of a throttle linkage provided for the metering device.

Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

AS SHOWN ON THE DRAWINGS In FIG. I is shown an internal combustion engine 10 provided with a pressurized fuel metering device 12 in accordance with one embodiment of the invention. A fuel pump 14 forms a part of the fuel metering device, although it is shown schematically in the drawing and is separate from the main housing of the metering device. Gasoline is supplied through the fuel pump 14 from the gasoline tank of the vehicle in which the engine is provided, only a portion 16 of the fuel line being shown.

Considering FIG. 2 along with FIG. 1, it may be seen that the main housing 34 of the metering device is mounted on a mixer or blender device 18 which in turn is mounted on the intake manifold 20 of the engine. The metering device supplies metered amounts of fuel and air to the mixer or blender 18 which in turn supplies the fuel-air mixture through the intake manifold 20 to the cylinders ofthe engine where the mixture is burned. Exhaust gases flow from the engine through exhaust manifolds 22 and 24 to exhaust pipes 26 and 28. Some of the exhaust gases are recycled through return conduits 30 and 32 back to the mixer or blender device 18 where they are mixed with the incoming fuel and air fed to the engine to be reburned. The mixer or blender device 13 may be constructed in accordance with either of the two copending applications identified above.

As shown in FIG. 3, the metering device 12 includes the fuel pump l4 and the main housing or block 34 in which various flow paths and valves are provided as will be described. Gasoline is supplied from pump 14 through a line 36 into the block 34. The device meters air as well as gasoline, and for this purpose a bore 38 forming an intake passage is provided through the block 34. Filtered air is supplied from an air filter through the bore 38 into the mixer or blender l8, and the rate of air flow is metered by means of a butterfly valve 40. Valve 40 is a circular disc mounted on a rod 42 which is mounted for rotation in the block 34. The rod 42 extends through the block 34 and projects from one side of the block as shown at the bottom of FIG. 3. The block 3 may be a unitary metal block.

The projecting end of rod 42 is connected by an arm 44 (see FIG. 7) 'to a throttle rod 46 which moves reciprocally in response to actuation of the accelerator of the vehicle in which the engine 10 is mounted. Arm 44 is pivotally connected to rod 46 by means of a pivot pin 48, and a reduced portion 50 of arm 44 extends through rod 42 and is secured thereto by a setscrew 52. Thus, the reciprocal motion of rod 46 causes rotation of rod 42 to open or close the butterfly valve 40 and thus regulate the flow of air through intake passage 38 leading to the mixer or blender 18 A gear 54 is affixed to rod 42 and meshes with another gear 56 which controls a fuel metering valve in a manner to be described later. It may be noted at this point, however, that the air metering valve and the fuel metering valve are operated together by a single throttle linkage. Other types of throttle linkages may be used. 1

FIGS. 4, 5 and 6 illustrate the interior of the block 34. Gasoline from the fuel pump 14 is supplied to'the block through line 36 which connects through a fitting 58 with a passage 60 (FIG. 6) leading to a well 62 in which a check valve is provided. The well 62 has a tapering bottom surface 64 against which a ball 65 is urged by a spring 66 (see FIG. 4). The upper end of spring 66 butts against a plug 68 which closes the well 62. The ball 65 normally closes the inlet passage 60. When the engine is running, it drives the fuel pump 14 in the usual manner for operating a fuel pump. The fuel pump 14 forces gasoline under pressure through passage 60, and this pressure raises ball 65 from surface 64 allowing gasoline to flow into the well 62. When the engine is shut off, ball 65 again seats on surface 64 to block passage 60.

A passage 70 leads from well 62 to a reservoir 72 for storing gasoline for idle supply purposes as will be explained. The reservoir 72 is closed by a plug 75. Passage 70 may intersect surface 64 just under the midpoint of ball 65. Thus, if excessive back pressure should develop in line 70, for example due to atmospheric pressure changes, it raises ball 65 enough to relieve the pressure, and the ball then closes. This is a safety device.

An idling fuel supply passage 74 leads from reservoir 72 to the intake passage 38. The idling supply passage 74 narrows down where it joins passage 38 to a very small orifice 76 through which gasoline is introduced into the passage 38. The

passage 74 also has a conical surface 78 forming a valve seat for a needle valve 80. The valve 80 is essentially a rod having a conical tip 82 adapted to seat on the valve seat 78, and also having a threaded portion 84 engaging matching threads in the block 34 so that the rod may be turned by manipulation of a knob 86 to move the rod axially. The valve 80 is normally open, and its position is adjusted to assure a proper flow of gasoline under the pressure of the pump M through passage 74 into the intake passage 38.

Another passage 88 leads from reservoir 72 to another reservoir 90 for storing gasoline for starting purposes as will be explained. The reservoir 90 is closed by a plug 92 as shown in H6. 5. A short passage 94 leads from reservoir 90 to a metering passage 96 which in turn connects with a tube 98 that projects into the intake passage 38. One end of tube 98 may be threaded and screwed into matching threads in the block 34 to connect with passage 96. Passage 96 has a conical surface 100 which provides a seat for a metering valve 102. Valve 102 is essentially a rod having a conical tip for seating on the surface 100. Valve rod 102 has threaded portion 104 which acts as a worm screw. The gear 56 referred to previously is mounted on the outer end of rod W2. Thus, when gear 56 is turned by reciprocal motion of the throttle rod 46, valve rod 102 moves axially to regulate the fiow of gasoline from reservoir 90 through passages 9d and 96 to the intake passage 38. The throttle linkage is constructed such that when the accelerator pedal of the vehicle is fully extended, the rod 102 seats on surface lili) to close the fuel metering valve. When the accelerator pedal is depressed, throttle rod 46 moves axially to turn gears 54 and 56, and thus moving rod 302 away from surface 100 to open the metering valve as needed to supply the required amount of fuel for operation of the engine.

All of the passages and reservoirs in the block 34 except passage 38 are normally full of gasoline. The threaded portions 84 and 104 of valve rods 80 and 102 respectively form seals which prevent leakage of gasoline from the reservoirs 72 and 90. External seals may also be provided if desired. The short passages U2 and 110 communicating respectively with reservoir 72 and well 62 are merely extensions of passages 88 and 70 where these passages have been drilled into the block 34. Passages 112 and 110 are closed by plugs 108 and 114.

When the engine is not running, valves 40 and 102 are closed, but valve 80 remains open. Even though valve 80 is open, fuel does not leak through passage 74 because the orifice 76 is very small and atmospheric pressure in passage 38 produces back pressure which holds gasoline in the passage 74. There is no air anywhere in the fuel path in block 34 except in passage 38, so gasoline does not leak from passage 74..

When the engine is runningat idling speed, the pump 14 forces gasoline under pressure through passage 74 and orifice 76 into intake passage 38 at the appropriate rate to maintain idling. Valve 102 is closed under these conditions.

When the engine is running at a speed above idling speed, valve 102 is also open so that gasoline is forced under pressure through supply passage 96 and tube 98 into intake passage 38. If the accelerator pedal is depressed, more gasoline is supplied through passage 96 to accelerate the vehicle, and if the accelerator pedal is raised less gasoline is supplied through passage 96 to decelerate the vehicle.

Due to the pressure of the pump 14, the liquid fuel is at least partially atomized and vaporized as it leaves orifice 76 and tube 98.

The reservoirs 72 and provide an immediately available supply of gasoline for starting purposes. Thus, when the en gine is initially starting and before pump pressure is built up, gasoline is available from reservoir 72 and reservoir 90 to start the engine. Reservoir 72 is not as important in this regard as reservoir 90, but the latter reservoir provides a static head of gasoline to assure flow of gasoline through passage 96 and tube 98 into passage 38 during starting. If the accelerator pedal should be pumped for some reason while the engine is not running, gasoline would flow from reservoir 90 through passages 94 and 96 and tube 98 into the intake passage 38. The reservoir 90 is large enough, however, to accommodate a considerable amount of pumping without completely draining the reservoir. Thus, there will be gasoline in the reservoir 90 available to start the engine even after substantial pumping with the engine off. if an air space is created in reservoir 90 as a result of such pumping, it is eliminated by the pressure of pump 14 when the engine starts.

Thus, the invention provides a device for metering fuel and air which are mixed and supplied to an internal combustion engine. When the engine is running, the fuel is under positive pressure, and when the engine is not running, back pressure is created which prevents leakage of fuel. The device has separate passages for allowing idling and acceleration of the engine. Note that the order or sequence of these passages is not critical; they could be reversed. At least one reservoir is provided to assure an immediately available supply of gasoline for starting purposes. An air metering valve and a fuel meter-- ing valve are controlled by a common linkage. Except for the pump, the device may be incorporated in a unitary block as i!- lustrated, and this block may be relatively small to conserve space in the engine. The device can be constructed economically on a mass production basis.

I claim:

1. A device for supplying metered amounts of fuel and air from a fuel pump to an internal combustion engine, said device including a metal block having a major plane with:

1. an intake passage extending through said block perpendicular to said major plane for receiving air to be supplied to the engine,

2. a first bore in said block parallel to said major plane communicating with said fuel pump,

. a first closed well in said block forming a reservoir to which said first bore leads,

4. a second bore in said block parallel to said major plane communicating between said first well and said intake passage for supplying fuel under pump pressure from said first well to said intake passage at a rate to sustain idling of the engine, said second bore having a minute discharge orifice so proportioned that fuel does not leak through said orifice when the engine stops due to the sealed nature of said block except at said orifice and also due to back pressureof the atmosphere at said orifice,

5. a second closed well in said block forming a second reservoir,

6. a third bore insaid block angular to said first bore and parallel to said major plane communicating between said first and second reservoirs,

7. a fourth bore passage parallel to said major plane compassage for supplyingfuel under pump pressure from said municating between said second reservoirand said intake first well to said intake passage at a rate to sustain idling passage for flow of fuel under pump pressure from sa d of the engine, said second bore having a minute discharge ec nd reservoir I Said intake P 8 orifice discharging into said intake passage and proporfuel metering valve means in Said fourth bore P g tioned so that fuel does not leak through said orifice when metering Valve means in Said intake P and the engine stops due to the sealed nature of said block exmeans for operating said fuel metering Valve means and cept at said orifice and also due to atmospheric back pressaid air metering valve means jointly to control the flow sure at said rifi of fuel and air to the engine said fuel metering Valve 6. a second closed well in said block forming a second resermeans normally closing said fourth bore passage when 10 Said operating means i deactivated but opening the same 7. a third bore in said block parallel to said major plane ul3on afimanon f opefatmg means to supply fuel communicating between said first and second reservoirs, from reservo'rs for stamng Purposes 8. a fourth bore passage parallel to said major plane com- 2. A device for supplying metered amounts of fuel and air from a fuel pump to an internal combustion engine, said device including a metal block having a major plane with:

1. an intake passage extending through said block perpendicular to said plane for receiving air to be supplied to the engine,

2. a check valve in said block connected to an output of said fuel pump to receive fuel under pressure therefrom,

. 3. a first bore in said block parallel to said plane and communicating with said check valve,

4. a first closed well in said block forming a reservoir to which said first bore leads,

5. a second bore in said block parallel to said major plane communicating between said first well and said intake municating between said second reservoir and said intake passage for flow of fuel under pump pressure from said second reservoir to said intake passage,

9. fuel metering valve means in said fourth bore passage,

10. air metering valve means in said intake passage, and

11. means for operating said fuel metering valve means and said air metering valve means jointly to control the flow of fuel and air to the engine, said fuel metering valve means normally closing said fourth bore passage when said operating means is deactivated but opening the same upon actuation of said operating means to supply fuel from said reservoirs for starting purposes. 

